不同 pH 值条件下利多卡因对淋巴细胞 β 受体的影响

THE EFFECTS OF LIDOCAINE ON LYMPHOCYTE β ADRENERGIC RECEPTOR AT DIFFERENT pH

用放射配基结合法和放免分析法测定了不同ｐＨ值下利多卡因对人血液淋巴细胞β受体结合和肾上腺素刺激的ｃＡＭＰ产量的影响。结果表明，ｐＨ值的增加有利于３Ｈ－ＤＨＡ与β受体结合，肾上腺素刺激的淋巴细胞ｃＡＭＰ的产量随ｐＨ值的增加而增加（Ｐ＜０．００１）；利多卡因抑制β受体结合和肾上腺素刺激的淋巴细胞ｃＡＭＰ产量，其抑制程度亦随ｐＨ值增加而增加（Ｐ＜０．００１）。提示心肺复苏期间不用利多卡因时β受体激动剂的效应随ｐＨ值的增加而增加，如同时使用利多卡因则β受体激动剂的效应并不随ｐＨ值的增加而增强，其机制可能与利多卡因随ｐＨ值的增加，改变了细胞膜脂质流动性，抑制β受体与激动剂的结合有关。

The effects of lidocaine on β adrenergic receptor binding and the yield of epinephrine stimulated cAMP at different pH were measured by radioligand binding assay and radioimmunoassay. The results showed that the binding of 3 H DHA to the receptor and yield of epinephrine stimulated cAMP increased with increasing pH( P <0.001) and lidocaine inhibitory potency also increased with increasing pH ( P <0 001); The results indicate that the response to β agonists would increase with pH during cardiopulmonary resuscitation when lidocaine is not present, but it would not increase with pH when lidocaine is present, suggesting that lidocaine may inhibit binding of β agonists to receptor by changing lipid fluidity of cell membrane with increasing pH.